Recently, as miniaturization, thin size, and high functions are demanded for electronic apparatuses such as mobile communication apparatuses, miniaturization, thin size, and high functions are required for semiconductor devices provided inside the electronic apparatuses. Because of this, for example, a CSP (Chip Size Package) type semiconductor device which is a package having dimensions equal to or slightly larger than those of the semiconductor element has been suggested.
However, a semiconductor device for an automobile may be operated under tough atmospheric conditions. Therefore, a surface mounted type semiconductor device using a lead pin such as a SOP (Small Outline Package) type semiconductor device or a QFP (Quad Flat Package) type semiconductor device has been used a lot.
As various electronic controls for automobiles have been recently developed, hybrid technologies have progressed, and automobile components are commonly used; therefore high throughput is required for manufacturing and testing steps of the related semiconductor devices. Especially, in order to eliminate primary defects, approximately eight through approximately forty eight hours are required for a burn-in process where an accelerated test is performed so that temperature and voltage stress are applied to the semiconductor device.
A related art burn-in board 1 used in the burn-in process is illustrated in FIG. 1.
An edge terminal part 2 is provided at one end part of the burn-in board 1 illustrated in FIG. 1. The edge terminal part 2 is connected to a burn-in apparatus not illustrated in FIG. 1. In addition, a large number of sockets 3 are mounted on a part of a main surface of the burn-in board 1 other than the edge terminal part 2. A semiconductor package 4 (see FIG. 2) is mounted on the socket 3.
The socket 3 illustrated in FIG. 1 and the semiconductor package 4 mounted on the socket 3 are illustrated in FIG. 2. In addition, the socket 3 mounted on the burn-in board 1 is illustrated in FIG. 3. The semiconductor package 4 is mounted on the socket 3 and a cover 5 is provided above the socket 3.
A semiconductor package mounting part 3a is provided in a substantially center of the socket 3. Plural contacts 3b having spring properties are provided outside the semiconductor package mounting part 3a. End parts of the contacts 3b are inserted in through holes 6 formed in the burn-in board 1 and fixed to the burn-in board 1 by solder. When contact parts 5a extending inside the cover 5 come in contact with the contacts 3b, the other end parts of the contacts 3b come in contact with leads 4a of the semiconductor package 4 mounted on the semiconductor package mounting part 3a. 
The leads 4a of the semiconductor package 4 are provided on two side surfaces facing each other of a resin part 4b. The resin part 4b seals the semiconductor element. The leads 4a are made of, for example, a copper (Cu) alloy or an iron-nickel (Fe—Ni) alloy.
The end parts of the contacts 3b of the socket 3 are positioned corresponding to the leads 4a of the semiconductor package 4. When the semiconductor package 4 is mounted on the socket 3 as indicated by an arrow in FIG. 2, the semiconductor package 4 is positioned by the socket 3 so that electrical contact between the contacts 3b and the semiconductor package 4 is obtained. The semiconductor package 4 has the same configuration as a semiconductor package just separated from a lead frame (not illustrated).
In addition, the following structure has been suggested. That is, an IC lead is sandwiched by a lid part and a burn-in board. The lid part has a pressing part configured to press the IC lead. The burn-in board has a contact stick configured to support the lead. See Japanese Patent No. 2920859.
However, in order to mount or remove the semiconductor packages 4 on or from a large number of the sockets 3 mounted on the burn-in board illustrated in FIG. 1, it is necessary to attach or detach one semiconductor package 4 for every socket 3. For example, in a case where a hundred (100) sockets 3 are mounted on a single burn-in board 1, it is necessary to attach or detach semiconductor packages 4 a hundred (100) times.
Because of this, even if the semiconductor packages 4 are attached to or detached from the sockets 3 by using an automatic machine, it is necessary to perform the above-mentioned operation for every socket 3 and therefore it takes a lot of time.
In addition, if the number of the sockets 3 to be mounted on the burn-in board 1 is increased, the number of the semiconductor packages 4 to be used one time in the burn-in apparatus (not illustrated) is increased so that the operational efficiency is increased. However, it is difficult to increase the mounting density of the sockets 3 illustrated in FIG. 1 through FIG. 3 on the burn-in board 1 due to the structures of the sockets 3 illustrated in FIG. 1 through FIG. 3.
That is, it is necessary to form electric circuits for applying the burn-in process to the electronic components such as the semiconductor packages 4, on the burn-in board 1. Therefore, elements such as resistors for a lead-connecting process of the semiconductor package 4 are frequently mounted on the burn-in board 1. With a structure where the socket 3 is mounted on the burn-in board 1 by inserting the contacts 3b to the through holes 6 formed in the burn-in board 1, the mounting area of the burn-in board 1 where the elements are mounted is positioned outside the area where the socket 3 is mounted. Hence, in a case where the socket 3 is mounted via the through holes 6, the mounting area of the elements is outside the IC socket 3 and therefore improvement of the mounting number is obstructed. Accordingly, it is difficult to increase the mounting density on the burn-in board 1 of the sockets 3.
In order to solve such a problem, a lead frame where un-diced plural semiconductor packages 4 are connected, not diced semiconductor packages 4, may be connected to the burn-in board 1. With this structure, since the number of the semiconductor packages 4 connected to a single lead frame is plural, it is possible to handle the semiconductor packages 4 in a lump so that the number of processes can be decreased.
However, in this structure, pitches of individual semiconductor packages 4 connected to the lead frame are narrow. Therefore, it is difficult to provide the contacts 3b of the socket 3 having spring properties in the narrow area. In addition, since processing conditions with high precision are requested for development of a small sized socket, processing cost may be high.
In addition, a probe pin, instead of the contact 3b having the spring property, may be used as a method for electrically connecting to the leads 4a provided to the semiconductor package 4 with narrow pitches. However, the price of a single probe pin is higher than that of the contact 3b and the number of assembling processes of the probe pin is greater than that of the contact 3b. Therefore, the manufacturing cost may be increased in an electrical connection to the lead 4a of the semiconductor package 4 by using the probe pin.
In addition, in a case discussed in Japanese Patent No. 2920859 where the IC lead is pressed by the pressing part of the lid part, the lead is pressed by the surface of the pressing part. Therefore, a large force may be required for removing an oxide film formed on the lead for electrical connection and thereby plastic deformation of the lead may occur.